Hi Laurent,
It looks like the materials/media you defined are not known by G3. Make
sure that in your MyMCApplication::ConstructGeometry() you do the folowing:
- set a top volume in your geometry: gGeoManager->SetTopVolume(top);
- close the geometry: gGeoManager->CloseGeometry()
- notify TGeant3 that you want to plug in your geometry:
gMC->SetRootGeometry();
Regards,
Andrei
Laurent Aphecetche wrote:
> Hi (again ;-) )
>
> I now have a sample VMC application (based for the moment on TGeant3,
> compiled with -DWITHROOT).
> Geometry seems ok, but as soon as I try to throw particles (Geantinos)
> in there, I get a crash :
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread -1085118976 (LWP 29109)]
> 0x4017853d in g3track_ () at gtrak/gtrack.F:118
> 118 CUTS(I) = Q(JTMN+I)
> Current language: auto; currently fortran
> (gdb) print I
> $1 = 1
> (gdb) print JTMN
> $2 = 16744448
>
> As far as I understand, this is linked to the media/materials parameters.
> So I assume my materials are ill-defined in some way.
>
> Any hint on the possible cause ?
>
> Thanks,
>
> PS: Here's the way I define my materials/media (inspired from E01 ; I
> assume the negative parameters means Geant3 will compute them
> automatically, is that correct ?) :
>
> TGeoManager* gm = ...
>
> Double_t a2[2] = { 14.01, 16.00};
> Double_t z2[2] = { 7.0, 8.0};
> Double_t w2[2] = { 0.7, 0.3};
> Double_t density = 1.29e-03;
> int imatair = 15;
>
> gm->Mixture("Air", a2, z2, density, 2, w2, imatair);
>
> int isvol = 0; // not a sensitive volume
> Int_t ifield = 2; // User defined magnetic field
> Double_t fieldm = 5.; // Maximum field value (in kiloGauss)
> Double_t epsil = .001; // Tracking precision,
> Double_t stemax = -0.01; // Maximum displacement for multiple scat
> Double_t tmaxfd = -20.; // Maximum angle due to field deflection
> Double_t deemax = -.3; // Maximum fractional energy loss, DLS
> Double_t stmin = -.8;
>
> fImedAIRF = 19;
> fImedAIRLOWF = 18;
>
> // AIR, High Magnetic Field
> gm->Medium("AIRF",fImedAIRF,imatair,isvol,
> ifield, fieldm, tmaxfd, stemax,
> deemax, epsil, stmin);
>
>
> // AIR, Low Magnetic Field
> fieldm = 1.0;
> gm->Medium("AIRLOWF",fImedAIRLOWF,imatair,isvol,
> ifield, fieldm, tmaxfd, stemax,
> deemax, epsil, stmin);
>
This archive was generated by hypermail 2b29 : Sun Jan 02 2005 - 11:25:00 MET